| CASE OF THE MONTH - December 2004 |
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History:
An 18 year old male NAIA college soccer player presented with right hip pain. The original injury occurred approximately four months ago, prior to the end of spring season, when he fell onto the right posterior hip causing minor discomfort. The right hip pain continued for the remaining two weeks of spring practice and resolved with rest during the summer vacation. On reporting to school in August, he was asymptomatic and initiated a plyometric training regimen. After the first week of drills, he developed posterior right hip pain that was also exacerbated by cutting and jumping activities.
He was treated conservatively by the athletic training staff with OTC NSAIDs, ROM and stretching exercises, and various other modalities, such as moist heat, ice, and galvanic stimulation. He improved minimally over the next month and was therefore referred to the sports medicine clinic.
The PMH was unremarkable. He denied any GU or back symptoms. |
Physical Exam:
Right hip had normal range of motion, as compared to the left, however the patient described pain at the extremes of internal and external rotation, and extension. Tenderness was noted over the posterior aspect of the proximal femur. Strength was 4 out of 5 with manual testing on flexion, extension, adduction, and external rotation. Neurovascular exam was normal. No masses were palpated. Genitourinary exam was unremarkable. |
Initial Differential Diagnosis based on the History and Physical:
1) hamstring muscle strain
2) avulsion injury
3) myositis ossificans
4) stress fracture of the femoral neck
5) “Sports hernia”
5) benign / malignant lesion
6) avascular necrosis the femoral head |
Diagnostic studies:
1) What lab test, radiographs, or other diagnostic studies would you order to aid in the diagnosis? |
Final Diagnosis:
Osteochondroma of the right proximal femur. |
Treatment and Outcome:
Treatment options were discussed with the athlete. It was decided to initiate conservative measures such as progressive rehabilitation, NSAIDs, increase activity as tolerated, and monitor for increasing pain. Surgery was an option but because of the location of the lesion, extensive procedure required, and the athlete wishes this would be saved as last resort after all conservative measures had failed. |
Discussion:
Osteochondroma is described as a benign exostoses; growth of aberrant foci of cartilage on the bony surface. Cartilage grows forming a cap over bony mass. Lesion may be pedunculated on a stalk or sessile. Lesions of the femur, proximal tibia, and proximal humerus account for two-thirds of the cases. Typical site is metaphysis of long bone. It is relatively common and presents during late childhood or adolescence. It is the most common benign bone tumor. It not thought to be neoplastic however there is a remote possibility of malignant transformation. Typical presentation is a firm mass of long duration. It may mechanically interfere with function. A bursa may form and produce pain.
A plain radiograph of a pedunculated osteochondroma is so characteristic that it is virtually pathognomonic.
Some of the associated complications of an osteochondroma include: locking knee, muscle restriction; compression of nerves, vessels, and muscles/tendons; vascular compromise such as stenosis, occlusion, and pseudoaneurysm; growth and angular deformity; fracture and bursitis; malignant degeneration.
Concerns for malignant transformation include continued growth after skeletal maturity especially with pain, and larger lesions (cartilaginous caps greater than 1.5 cm). Multiple hereditary exostoses is a less common variant that is inherited as an autosomal dominant trait. It has a higher association of malignant conversion.
Osteochondromas typically do not routinely need to be removed. Some studies have shown as high as 12% complication rate following excision. The main reason for removal of these lesions is pain, fracture, nerve irritation, continued growth in a skeletally mature patient, and concern about cosmetic appearance.
In this case, we decided to pursue MRI of the lesion because of size of the lesion on plain radiographs and the chronic nature of his pain. He was advised to have periodic follow up with a physician. |
Referencess:
1) Morris CD, Lee FY, Gebhardt MC. In: Chapman MW, Lane JM, Mann RA, Marder RA, McLain RF, Rab GT, Szabo RM, Vince KG, eds. Chapman’s Orthopedic Surgery. 3rd ed. Philadelphia, PA; Lippincott Williams & Wilkins: 2001: Chapter 127.
2) Siebenrock KA, Ganz R. Osteochondroma of the femoral neck. Clin Orthop. 2002 Jan; (394):211-218.
3) Miller SL, Hoffer FA: Malignant and benign bone tumors. Radiol Clin North Am. 2001 Jul; 39(4):673-99. |
Case provided by:
David S. Ross, MD is Director of the Methodist Hospitals of Dallas Primary Care Sports Medicine Fellowship |
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